The present invention relates to an active medullary nail for distraction of bone segments, comprising two elements, prosthesis, or the like, which can be moved relative to each other, with at least one electrically operated drive element.
Medullary nails of this type are known and available on the market in a very wide variety of forms and designs. It is becoming more and more common for electrical drive elements to be provided in the medullary nails in order to generate a distraction of two elements which are movable relative to each other. To do this, electrical connections are necessary for operating the medullary nail.
A disadvantage of the previously known connections is that these are embedded directly in the medullary nail and are often broken or damaged as a result of being moved many times if distraction takes place over a certain period of time, or as a result of external influences, for example movement of the limbs.
A further disadvantage is that these connections are removed following a specified distraction, for example by surgery or being cut through. Then, in the event of a renewed distraction, this connection has to be surgically connected up again, which is time-consuming.
It is an object of the present invention to make available an active medullary nail for distraction and also a medullary nail with optionally attached prostheses or the like, with which an electrical connection can be established in a very simple way. This is intended to fulfill the electrical, mechanical and hygiene requirements.
To achieve this object, the electrical energy can be delivered to the medullary nail via at least one detachable plug element.
A socket is provided in an opening preferably at one end of one of the two axially displaceable elements of the medullary nail. A plug element can be inserted there into an opening in order to establish an electrical connection for control and energy transmission. In this arrangement, completely standard plugs or plug connections can be used, as are described for example in DIN-ISO 5841-3. A bipolar design is preferred. A plurality of electrical signals can be transmitted.
It has proven particularly advantageous for at least one sealing lip element to be assigned to the plug element, preferably at the end. This sealing lip element is elastic and is preferably designed tapering outward. It closes off the opening of the socket completely and in an absolutely leaktight manner. In this way, no tissue fluid or the like can gain entry and damage the electrical connection between socket and plug element.
It is also advantageous in the present invention that the medullary nail be designed as a prosthesis and that after a desired period of distraction only the electrical plug connection be surgically removed. The opening can then be closed with a stopper or the like. Should further distraction prove necessary, the stopper can be surgically removed again and the plug then inserted there. This affords considerable advantages in particular in operating and handling active medullary nails of this type.